Convert 21 Gigawatt (GW) to Joule/Second (J/s).

21 Gigawatt equals 21,000,000,000 Joule/Second. Multiply 21 by 1,000,000,000.

21 Gigawatt = 21,000,000,000 Joule/Second

Worked example: converting Gigawatt to Joule/Second

Step 1 — start with the formula. J/s = GW × 1.000000e+9
Step 2 — substitute your figure. 21 GW × 1,000,000,000
Step 3 — read the result. 21 GW = 21,000,000,000 J/s
Step 4 — check it in reverse. GW = J/s × 1.000000e-9 returns Invalid GW, which matches the figure you started with.

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From

To

21,000,000,000

21 GW = 21,000,000,000 J/s

Formula:

J/s = GW × 1.000000e+9

With your value: 21 GW = 21,000,000,000 J/s

How big is that?

Everyday references on a logarithmic scale, all expressed in gigawatt so you can sanity-check the result.

LED bulb (1/2.3e+9 your value)9.00e-9 GW

Laptop (1/3.2e+8 your value)6.50e-8 GW

Microwave oven (1/2.1e+7 your value)0.00000100 GW

Electric kettle (1/7.0e+6 your value)0.00000300 GW

Family car engine (1/2.3e+5 your value)0.0000900 GW

Your value21.0 GW

Other Gigawatt to Joule/Second conversions

15 GW to J/s 16 GW to J/s 18 GW to J/s 20 GW to J/s 24 GW to J/s 25 GW to J/s 26 GW to J/s Full Gigawatt to Joule/Second converter

Gigawatt to Joule/Second Conversion Table

Gigawatt (GW)	Joule/Second (J/s)
0.5	500,000,000
1	1,000,000,000
2	2,000,000,000
5	5,000,000,000
10	10,000,000,000
15	15,000,000,000
20	20,000,000,000
25	25,000,000,000
50	50,000,000,000
100	100,000,000,000
250	250,000,000,000
500	500,000,000,000
1000	1.000000e+12

Joule/Second to Gigawatt Conversion Table

Joule/Second (J/s)	Gigawatt (GW)
0.5	5.000000e-10
1	1.000000e-9
2	2.000000e-9
5	5.000000e-9
10	1.000000e-8
15	1.500000e-8
20	2.000000e-8
25	2.500000e-8
50	5.000000e-8
100	1.000000e-7
250	2.500000e-7
500	5.000000e-7
1000	1.000000e-6

Where these values come from

Every factor on this page is traced to the document that defines it. See the full provenance dataset or our methodology.

Gigawatt (GW)

Power

Exact conversion

Derived from the watt (1 W = 1 J/s).

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

Joule/Second (J/s)

Power

Exact conversion

Derived from the watt (1 W = 1 J/s).

Source: NIST Special Publication 811, Guide for the Use of the International System of Units

National Institute of Standards and Technology (US) · Reviewed 2026-07-01

How to Convert Gigawatt to Joule/Second

To convert from Gigawatt (GW) to Joule/Second (J/s), multiply the value by 1,000,000,000.

Formula: J/s = GW × 1.000000e+9

Reverse: GW = J/s × 1.000000e-9

Step-by-Step Example

Start with your value in Gigawatt. For example: 5 GW
Multiply by the conversion factor: 5 x 1,000,000,000
The result is: 5,000,000,000 J/s

About Gigawatt

The gigawatt (GW) is a unit of power. One gigawatt equals 1.000000 × 10^+9 watts. UnitConvertLab converts it against every other power unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: power calculations, engineering and science, education.

About Joule/Second

The joule/second (J/s) is a unit of power. One joule/second equals 1 watt. UnitConvertLab converts it against every other power unit using this exact definition, so results are reproducible to full double precision rather than rounded lookup tables.

Common uses: power calculations, engineering and science, education.

Frequently Asked Questions

What is 21 Gigawatt in Joule/Second?

21 Gigawatt equals 21,000,000,000 Joule/Second.

How many Joule/Second are in 1 Gigawatt?

There are exactly 1,000,000,000 Joule/Second in 1 Gigawatt. This means the conversion factor from Gigawatt to Joule/Second is 1,000,000,000.

What is the formula to convert Gigawatt to Joule/Second?

The formula to convert Gigawatt to Joule/Second is: J/s = GW × 1.000000e+9. For example, to convert 10 Gigawatt to Joule/Second, you would multiply 10 by 1,000,000,000.

What is a Gigawatt?